Machine for mixing concrete and other granular materials



April 2, 1935. N. HARRISON 1,996,543

MACHINE FOR MIXING CONCRETE AND OTHER GRANULAR MATERIALS Filed Feb. 21, 1934 2 Sheets-Sheet 1 MVE/VTO/P. Noam HARRISON.

A ril 2, 1935. N, HARRISON 1,996,543

MACHINE FOR MIXING CONCRETE AND OTHER GRANULAR MATERIALS Filed Feb. 21, 1934 2 Sheets-Sheet 2 Fig 2 Harm/sou. B)

Patented Apr. 2, 1935 MACHINE FOR MIXING CONCRETE AND OTHER, GRANULAR MATERIALS Norman Harrison, Low Fell, England Application February 21, 1934, Serial No. 712,422 In Great Britain January 21, 1933 2 Claims.

This invention relates to machines for mixing concrete and other granular materials of the kind comprising a rotary mixing pan having a central.

discharge door in the bottom of the pan.

The invention has for its object to provide means for effecting the rapid discharge of the mixing pan.

According to the invention a deflector plate is arranged to extend from the wall of the pan to the edge of the central opening, the said plate being mounted so that it may be raised from the bottom of the pan while mixing is in progress. Preferably means for raising the plate are combined with the means for opening the central discharge door so that the plate comes down into position when the door is opened.

The invention will now be described by way of example with reference to the accompanying drawings which show a portion of a concrete mixer comprising means for opening the discharge door at the same time that the deflector plate is lowered.

In the said drawings:

Fig. 1 is a plan view.

Fig. 2 is a side elevation.

Fig. 3 is an end elevation.

Referring more particularly to the drawings, l is the mixing pan, and 2 the discharge door which is of the kind comprising a rotatable closure member mounted on an arm 3 which in its turn is mounted on a shaft 4 extending to the side of the machine frame, the outer end of the shaft 4 having an arm 5 which when the door 2 is in the closed position is in a substantially horizontal position, a weight 6 on the arm 5 maintaining the door closed. To ensure the arm 5 remaining in the open position it is connected by lost motion means with the arm 3 so that when the door is opened the arm 5 is well past the vertical centre line. On the outer end of the said transverse shaft 4 a second arm 1 is mounted and is connected by a connecting rod 8 and a universal joint 9 to the outer end of a lever Ill having its fulcrum on a frame H extending over the mixing pan l. The said frame I I has provided thereon four vertical bearingsJZ through which pass two rods I3 which at their upper ends are secured to a horizontal member l4 connected at its midpoint to the inner end of the lever l0, while at their lower ends the rods l3 are rigidly secured to a deflector plate IS.

The deflector plate I5 is concave with respect to the direction of rotation of the pan and is at an angle of substantially 45 to the latter. The inner end of the plate I5 is curved more sharply to ensure the material being carried well over the edge of the opening while discharge is taking place.

The connections between the lever arm l0 and 10 the arm 1 are such that when the arm 5 is raised to open the door the lever In is rocked to bring the deflector plate l5 into position at the bottom of the pan as shown in chain lines; while when the door 2 is closed the lever I0 is rocked to raise 5 the deflector plate l5 off the bottom of the pan to such a height shown in dotted lines that it will clear the material in the pan I.

I claim:'--

1. In a machine for mixing concrete and other 20 granular materials of the kind described, comprising a rotary mixing pan having a central opening,

a deflector plate extending from the wall of the pan to the edge of the central opening, a shaft extending to the side of the machine, a closure 25 member for said opening mounted on said shaft, an arm on said shaft, a lever, a connecting rod and universal joint connecting said arm to the outer end of said lever, vertically slidable rods in the mixing pan, said rods carrying at their lower ends the deflector plate and a pivotal connection between the inner end of said lever and said vertical rods, the arrangement being such that the deflector plate is raised when the closure memher is closed.

2. In a machine for mixing concrete and other granular materials of the kind described, comprising a rotary mixing pan having a central opening, a deflector plate extending from the wall of the pan to the edge of the central opening, a door for closing said central opening, means for actuating said door, and means interconnected with said door actuating means so that when the door is actuated to open the central opening, the deflector plate is moved to the bottom of the pan, and when the door is actuated to close the said central opening, the deflector plate is raised from the bottom of the pan.

NORMAN HARRISON. 

